Industrial installations often include systems using a fluid under pressure to perform control functions. Where the fluid is a gas, it is often air and systems using pressurized gas are called "pneumatic" systems. Where the fluid is a liquid, it is often oil under pressure and such systems are referred to as "hydraulic."
Such systems are used to power assembly tools, cylinders, automatic production tools, small hoists, dental and surgical equipment, among many others. One need only walk through a modern manufacturing plant to see pneumatic and/or hydraulic control valves and systems at work.
Persons using valves and other control devices, including but not limited to pressure and vacuum regulators, frequently arrange them in a control "network." Often, construction of the network requires connection of different types of fittings to a valve body and interconnection of valve bodies to one another. And later network modifications frequently dictate reconnection of the network components.
A major problem with known valve products is lack of porting flexibility. That is, the user is required to stock a relatively large number of "dedicated" fittings, manifold blocks, connectors, clamps and the like. And if an error is made during original connection or if the network needs to be rearranged, significant disassembly is often required.
U.S. Pat. No. 2,357,755 (Moll) shows a wiring conduit fitting with a box-like body, a plate-like body closure and provisions for making a coupling at each of three sides of the body. A coupling cannot be made at the fourth side of the body where the closure is attached. The body has a dovetail slot extending in a continuum around three of its sides and each slot portion receives a cover, the side edges of which are bevelled to fit the slot. A disadvantage of the Moll arrangement is that no cover (whether blank or "ported") can be removed without removing at least the non-ported main closure.
U.S. Pat. Nos. 3,560,027 and 3,538,940 (Graham) recognizes the need for improved flexibility and porting but propose a somewhat complex solution. A distribution block has a ported, dovetail-like slot on each of four faces. The port fittings inserted axially to the port and retained in place by a U-shaped clip which engages the slots on the distributor block and a shoulder on the port fitting.
U.S. Pat. No. 3,917,318 (Legris) shows yet another approach involving a rectangular block-like body with a dovetail projection on one face and intersecting dovetail grooves on the opposite face. The patent only describes how to attach bodies to one another using the dovetail projection/slot arrangement. In other words, the described invention is a "building block" mounting system.
U.S. Pat. No. 3,869,000 (English); U.S. Pat. No. 4,011,532 (Williams et al.) and U.S. Pat. No. 1,173,061 (Tregloune) all show sliding couplers of one type or another. U.S. Pat. No. 4,289,335 (Olbermann) and U.S. Pat. No. 3,130,985 (Oliveau) show arrangements joining two components together using something of a tongue and groove arrangement with a releasable clamp.
Product literature by SMC Pneumatics mentions a porting adapter with a clamp bracket placed over the adapter for retention. Product literature by Watts FluidAir describes what it calls the QUBE system which uses modular blocks for porting. The ports are integral to the block and cannot be changed without at least a degree of system disassembly and block substitution.
The modular system shown in product literature by Wilkerson includes modular insert, connection and manifold blocks with slanted bevelled edges. They are held to one another (or to a regulator body or the like) by a clamping modular sleeve slide-fitted over the edges.